Numerous constructural arrangements implementing manually-operated dispensers for discharging a quantity of fluid from an internal storage reservoir are known in the art. Such dispensers have been employed in a variety of applications, and for discharging many types of fluids in gaseous, liquid and flowable plastic states. Dispensers intended for sale to and use by consumers for discharging a cosmetic fluid onto an integral applicator when actuated by such a user comprise a particularly common application for dispensers of this kind.
Cosmetic fluid dispensers for manual user operation must be capable of relatively inexpensive fabrication from readily available materials. While it is important to minimize manufacturing costs, however, such dispensers must generally be fabricated to close tolerances to insure proper fit and cooperative interengagement between both fixed and relatively moveable parts and, further, to provide for reliable operation of the dispenser throughout its intended useful life--most typically until the initial supply of stored fluid is exhausted. Assuring continued operative reliability is made more difficult by the often hostile characteristics of the specific cosmetic fluids being stored and dispensed such as, for example, nail enamels which are relatively caustic to many common construction materials and which quickly thicken and harden in the absence of adequate fluid-tight seals bounding those portions of the dispenser exposed to or containing the dischargable fluid. Many heretofore known and commercially implemented dispenser constructions employ relatively complex mechanical designs which incorporate large numbers of mutually engaging parts that must all cooperatively interact for successful operation of the device. Dispenser constructions of this type are difficult and expensive to fabricate and often suffer an unusually high failure rate as the devices approach the end or latter portion of their intended useful lives. The aesthetic appearance of known dispensers--which is not uncommonly a significant and important part of their allure to the consumer at the point of sale--also often declines significantly from their pre-sale condition as the devices are repeatedly used, becoming less and less attractively appealing to the user. Soiling of the user's hands is also a not atypical problem as the discharged fluid, after repeated actuations of the dispenser, begins to cover exposed portions of the fluid-discharge end of the device and to leak onto and within an associated closure cap.